Source of two-dimensional electron gas in unintentionally doped AlGaN/GaN multichannel high-electron-mobility transistor heterostructures
Source of two-dimensional electron gas in unintentionally doped AlGaN/GaN multichannel high-electron-mobility transistor heterostructures
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非故意掺杂AlGaN/GaN多沟道高电子迁移率晶体管异质结构中二维电子气的来源
DOI：
10.1063/5.0045910
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发表时间：
2021-03
影响因子：
4
通讯作者：
R. Lingaparthi;N. Dharmarasu;K. Radhakrishnan;A. Ranjan;Tian Long Alex Seah;L. Huo
中科院分区：
文献类型：
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作者：
R. Lingaparthi;N. Dharmarasu;K. Radhakrishnan;A. Ranjan;Tian Long Alex Seah;L. Huo
利用等离子体辅助分子束外延技术在SiC衬底上制备了非有意掺杂（UID）AlGaN/GaN基多沟道高电子迁移率晶体管（MC-HEMT）异质结构。GaN沟道厚度为100 nm的MC-HEMT异质结构导致六个GaN沟道上的累积二维电子气（2DEG）浓度为4.3 × 1013 cm-2。样品显示出170 Ω/sq的薄层电阻。101 Ω/sq。分别在室温和90 K下。研究了异质结埋层GaN沟道中2DEG的来源。在UID MC-HEMT上进行的C-V测量排除了价带是2DEG源的可能性，以及随后在掩埋GaN沟道/AlGaN势垒界面处形成二维空穴气的可能性。实验获得的2DEG浓度与模拟数据的比较表明，在掩埋的GaN沟道/AlGaN势垒界面处存在类似供体的陷阱态，位于价带上方0.6至0.8 eV处，充当UID MC-HEMT异质结构中2DEG的来源。
Unintentionally doped (UID) AlGaN/GaN-based multichannel high electron mobility transistor (MC-HEMT) heterostructures have been demonstrated on the SiC substrate using plasma-assisted molecular beam epitaxy. The MC-HEMT heterostructure with a GaN channel thickness of 100 nm resulted in a cumulative two-dimensional electron gas (2DEG) concentration of 4.3 × 1013 cm−2 across six GaN channels. The sample showed sheet resistances of 170 Ω/sq. and 101 Ω/sq. at room temperature and 90 K, respectively. The source of 2DEG in the buried GaN channels of the heterostructure was investigated. The C–V measurements conducted on UID MC-HEMTs excluded the possibility of the valence band being the source of 2DEG and the consequent formation of two-dimensional hole gas at the buried GaN-channel/AlGaN-barrier interfaces. A comparison of the experimentally obtained 2DEG concentration with the simulated data suggests the presence of donor-like trap states, situated at 0.6 to 0.8 eV above the valence band at the buried GaN-channel/AlGaN-barrier interfaces, which act as the source of 2DEG in UID MC-HEMT heterostructures.